During turbine operation, many components are exposed to high temperature, high pressure conditions. Additionally, various air-stream particles contact the components as they travel through the turbine. Under the high temperature, high pressure conditions, the air-stream particles may deposit on the surface of the components, particularly on rear stage compressor blades.
One method of reducing deposition of particles includes coating compressor blades with an inner layer of aluminum particles, and an exterior coating of ceramic alumina flakes. The exterior coating of ceramic alumina flakes forms the outer surface of the component, and provides some erosion protection. However, the air-stream in a turbine often includes iron oxide particles, which may adhere to the ceramic alumina flakes on the surface of the compressor blades.
Another method of reducing deposition of particles includes the use of anti-stick compounds. Most currently used anti-stick compounds are limited to polytetrafluoroethylene (PTFE) like materials having a temperature limit of 250° F. These anti-stick compounds are not suitable for use with rear stage compressor blades, which are exposed to temperatures of 1000° F. or more.
A coating, coating system, and coating method with improvements in the process and/or the properties of the components formed would be desirable in the art.